Proposed studies include: (a) Monotic and dichotic identification and discrimination of speech-like and other complex auditory patterns, (b) objective tinnitus and evidence for auditory frequency analysis, (c) processes in vowel perception, (d) psychoacoustic measurements of chinchilla, (e) comparison of human and chinchilla processing of auditory signals, (f) structural, physiological, and psychoacoustic changes following prolonged and intermittent exposure to noise, (g) design goals and selection procedures for hearing aids, (h) processes in lipreading, (i) development of tests of language and of speech production for deaf children, (j) ipsilateral acoustic reflexes, (k) refinement of brain-stem evoked-response audiometry.